I've been given keys to someone's room before and typically, I immediately apologize, explain what happened and leave quickly so as to not create an awkward situation. Sounds like OP met a social media loser who was obviously relishing videoing the situation.

This reminds me of when I was staying at a 5-star island resort once, where a wedding-party had taken over most of the resort. At around 7 PM, there was loud pounding on my door and raucous laughter. I answered the door, only to have 5 or 6 young women rush into my room for the "bridesmaids' party". I am standing there, wearing only a swimsuit, and said that they must have the wrong room. They disagreed, but then I said, "well, what I am doing here if it's a bridesmaids' party?" (me being a large, hairy man). They suddenly looked embarrassed and rushed out the door, giggling all the way.